The objective of this work is the structural analysis of several glycoprotein hormones associated with reproduction, including human luteinizing hormone and follicle-stimulating hormone from the human and porcine species. No chemical characterization of porcine FSH has yet been reported. We have recently completed purification of the hormone, and physical-chemical and conformational properties as well as chemical characteristics are currently being evaluated. Sequence analysis of the separate subunits will then commence. While amino acid sequences of the two human hormones have been reported by other laboratories, a number of discrepancies are evident among the published structures which await independent confirmation. We have completed analysis of the alpha subunit of human LH, and the beta subunit is nearing completion. Human FSH subunits are being prepared for similar structural study with emphasis on the beta subunit where the major discrepancies are found. Comparative structural study of the separate carbohydrate side chains of the beta subunits of hLH and human chorionic gonadotropin are also in progress. Using the peptide fragments obtained during structural analysis, region-specific antisera are being prepared, both by characterization of existing antisera and direct animal immunization with the peptides themselves. These will be used in probing for fragments or altered metabolic forms of hormone in the circulation, and in neutralization experiments aimed at defining the structural requirements for biological and immunological activity and subunit interaction.